Renju VCF #4996429 (5-move VCF)
To move: Black — find the move that forces a win by fours
Winning line
G9 → G10 → G6 → G5 → F6 → E6 → E5 → D4
Why this move works
The answer is G9. From G9 you keep playing fours that force White's blocks (G9→G10→G6→G5→F6→E6).
The final E5 is a double threat White cannot fully stop, and D4 makes five — a five-move VCF.